From 483c948324a3823871c004560a92545759d3253c Mon Sep 17 00:00:00 2001 From: Sean Rhodes Date: Mon, 6 Jul 2026 16:40:43 +0100 Subject: [PATCH] misc: rtsx_usb: avoid USB I/O in runtime autosuspend The runtime autosuspend callback currently queries card status and clears OCP by issuing USB register accesses. This can run from the USB runtime-PM path itself, which is the wrong place to start more device I/O. Keep a cached copy of the card-status bits from normal status reads instead. During runtime autosuspend, use that cached value only to preserve the existing Memory Stick autosuspend deferral. Do not treat raw SD_CD as an autosuspend blocker, because tray-based SD readers can assert SD_CD with an empty tray. A real SD card is protected by the SD/MMC child runtime-PM usage once powered. Also stop clearing OCP from the runtime autosuspend callback, so the callback does not issue USB commands. Fixes: bb400d2120bd ("mfd: rtsx_usb: Defer autosuspend while card exists") Signed-off-by: Sean Rhodes Acked-by: Greg Kroah-Hartman Signed-off-by: Ulf Hansson --- drivers/misc/cardreader/rtsx_usb.c | 26 ++++++++++++++++++++------ include/linux/rtsx_usb.h | 3 +++ 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c index 1830e9ed2521..a127744918f4 100644 --- a/drivers/misc/cardreader/rtsx_usb.c +++ b/drivers/misc/cardreader/rtsx_usb.c @@ -312,6 +312,9 @@ int rtsx_usb_get_card_status(struct rtsx_ucr *ucr, u16 *status) if (ret < 0) return ret; + ucr->card_status_cache = *status; + ucr->card_status_valid = true; + return 0; } EXPORT_SYMBOL_GPL(rtsx_usb_get_card_status); @@ -623,6 +626,7 @@ static int rtsx_usb_probe(struct usb_interface *intf, { struct usb_device *usb_dev = interface_to_usbdev(intf); struct rtsx_ucr *ucr; + u16 status; int ret; dev_dbg(&intf->dev, @@ -659,6 +663,9 @@ static int rtsx_usb_probe(struct usb_interface *intf, if (ret) goto out_init_fail; + /* Prime cached status for runtime autosuspend decisions. */ + rtsx_usb_get_card_status(ucr, &status); + /* initialize USB SG transfer timer */ timer_setup(&ucr->sg_timer, rtsx_usb_sg_timed_out, 0); @@ -713,22 +720,29 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf); u16 val = 0; + bool valid = false; dev_dbg(&intf->dev, "%s called with pm message 0x%04x\n", __func__, message.event); if (PMSG_IS_AUTO(message)) { if (mutex_trylock(&ucr->dev_mutex)) { - rtsx_usb_get_card_status(ucr, &val); + valid = ucr->card_status_valid; + if (valid) + val = ucr->card_status_cache; mutex_unlock(&ucr->dev_mutex); - /* Defer the autosuspend if card exists */ - if (val & (SD_CD | MS_CD)) { + /* + * Do not issue USB commands from runtime autosuspend. + * Raw SD_CD is not authoritative on tray-based readers, + * while a real SD card is protected by the SD/MMC child + * runtime-PM reference once the card is powered. Keep + * the historical Memory Stick autosuspend deferral when + * the cached status says MS media is present. + */ + if (valid && (val & MS_CD)) { device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child); return -EAGAIN; - } else { - /* if the card does not exists, clear OCP status */ - rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_CLEAR, MS_OCP_CLEAR); } } else { /* There is an ongoing operation*/ diff --git a/include/linux/rtsx_usb.h b/include/linux/rtsx_usb.h index 276b509c03e3..0fc5a74700a8 100644 --- a/include/linux/rtsx_usb.h +++ b/include/linux/rtsx_usb.h @@ -61,6 +61,9 @@ struct rtsx_ucr { struct timer_list sg_timer; struct mutex dev_mutex; + + u16 card_status_cache; + bool card_status_valid; }; /* buffer size */